HISTORIC INTERIOR SPACES NUMBER 3

Preserving Historic Corridor Doors and Glazing in High-Rise Buildings

Chad Randl Technical Preservation Services National Park Service

Introduction

Historic office building corridors are building undergoes a major rehabilita­ often rich in distinctive features and tion or change in occupancy classifica­ materials. Glass door panels with gold tion, the owner is usually required to leaf lettering, glass transoms and side­ bring the structure into compliance with lights, woodwork and wainscoting all modem codes written primarily for new provide a physical connection to the way construction. Among other provisions, business was conducted in the late 19th current building codes often require that century. Moreover, they display a level assemblies and materials provide a spec­ of detail, and quality of material and ified level of fire resistance. Historic craftsmanship that are rare in new con­ doors, transoms and sidelights are com­ struction. Some of the same characteris­ mon corridor features that are unlikely to tics that make historic corridors signifi­ meet such resistance ratings (see cant and unique, however, may present a figure J). challenge to their sensitive rehabilitation. Building code enforcement has tradi­ When rehabilitating larger A primary difficulty lies in bringing tionally favored replacing existing mate­ buildings, significant corridors historic features and materials "up to rials and assemblies with new construc­ should be preserved where code." Because successive building reg­ tion of known fire rating. In recent possible. Code required changes ulations are rarely applied retroactively, years, however, regulatory and technical a historic structure may be decades - or solutions have better reconciled historic should be made in such a manner even a century - out of step with current features with life safety and building as to preserve important features life safety standards. When such a code requirements. Rehabilitation provi- and finishes. sions and equivalency and performance­ municipalities incorporate per­ .. based standards permit building officials fonnance-based components increased flexibility in detennining how into their fire code. existing historic construction can meet Performance-based codes current requirements. Meanwhile, man­ establish life safety goals that ufacturers and designers have responded fue protection engineers then with new materials and assemblies that use to develop a protection are more fire resistant. This plan that is unique to a partic­ Preservation Tech Note discusses some ular structure. Computer of the techniques applied when historic modeling and other fonns of office corridor features are modified to analysis allow the engineer to meet modem safety standards. The con­ consider every aspect of a version of two early skyscrapers in building'S design, construction Chicago for new functions illustrate and use. Originally developed ways of complying with fire regulations to give architects additional while retaining original materials and freedom in designing uncom­ assemblies. mon building types, perform­ ance-based systems are also Building Codes and Historic well suited to assessing and Office Corridors retaining historic features. Efforts to accommodate the unique All fire codes share one pri­ nature of historic features while uphold­ mary objective - to ensure the ing the safety of occupants and the safe evacuation of a burning building itself are increasingly reflected building. Because the corri­ both in newly written rehabilitation dors in high-rise buildings Figure I. Historic corridor features such as doors, transoms and codes and how older codes are adminis­ typically function as primary sidelights often do not meet current fire resistance regulations. tered. Traditionally codes have been escape routes, fue protection Photo: Fisher Building, Frank Merrill Photography. prescriptive, in that they identify all of solutions are designed to pre­ the steps necessary to achieve compli­ vent smoke and flames from spreading non-combustible material behind the ance. For example, the code may through and across the space. Valuable door or glass. The panels, usually gyp­ require that stairways used for egress escape and emergency service response sum board, calcium silicate board or have a two-hour fire separation and time is gained by restricting the rate at sheet steel, supplement the inadequate that sprinklers be located at specified which fire and smoke spread. Most pre­ level of protection provided by the origi­ nal glass or wood panels, thereby intervals. scriptive building codes stipulate a one­ achieving the desired rating. If the side­ Standard code requirements, however, hour fire rating for corridors. The wall lights or transoms are particularly large, do not take into account the individual assemblies separating offices or resi­ new partitions can be constructed behind characteristics of a building and are not dences from areas used for public egress easily applied to existing structures. must be able to resist heat and maintain the original walls (within the room or office units), again using non-com­ To address these issues, most codes their structural integrity for at least one bustible material. Smoke-resistance can allow authorities to consider alternative hour during a fue. Door openings that be increased by applying intumescent approaches often based upon the concept perforate such a wall assembly must have of "equivalency." If existing features are a 20-minute rating. Additional provi­ materials such as paint, paste or sealing strips to the space between the edge of code deficient, architects and building sions may limit the amount of glazed sur­ the door and the frame. These products officials may be able to retain them by face area and the types and characteris­ expand to several times their original establishing safety measures that provide tics of wall and door glazing. thickness when heated, forming a seal an equivalent level of protection to that Although historic masonry walls with that prevents the passage of smoke and stated in the code. Fire detection and two faces of plaster and solid wood doors flames. Intumescent stains, clear var­ automatic sprinkler systems, for exam­ may meet these basic requirements, most nishes and paints can also be used to ple, may be expanded beyond minimum doors, door panels, sidelights and tran­ raise the flamespread resistance of corri­ code requirements in order to permit the soms will probably be considered non­ dor trim and wainscoting. retention of historic features that are not conforming elements that require some When major assemblies such as doors code compliant. This provision is set form of alteration. Such code deficien­ and whole wall sections are preserved, a forth in the National Fire Protection cies were often corrected in the past by range of other features can also be Association's model code for historic replacing historic doors with solid doors retained. For example, if historic doors structures (NFPA 914) which states, and filling in or removing glazed areas are kept, it is likely that surviving hard­ "Nothing in this code shall be intended along corridor walls. However, an ware and trim can also be preserved and to prevent the use of systems, methods, increasing body of research and prece­ integrated into the new function. If his­ or devices of equivalent or superior dent indicates that the fire resistance of toric wall assemblies can be modified to quality, strength, fire resistance or effec­ historic corridor features can be meet code, the original dimensions, door tiveness," provided documentation of the improved with relatively simple modifi­ locations, trim, flooring and spatial equivalency is submitted and accepted cations that have little impact upon the organization of the entire corridor can be by the code authority. features. retained. Fire protection options available to One successful technique developed to Two separate structures built in those working with historic buildings will upgrade the fire resistance of historic Chicago during the last decade of the expand even further as many states and doors and glazed areas is to add sheets of

2 19th century were recently rehabilitated A" office space for their time. Mahogany hour of fire resistance, with a twenty using these approaches to save historic doors with glass upper panels and lower minute rating for guest room doors. corridor features and meet building and panels of wood provided entry to indi­ Glass sidelights and transoms and both fire code requirements. The Reliance vidual offices. Four-foot high white wood and glass door panels throughout and Fisher buildings, both originally Carrara marble wainscoting ran the the historic floors did not meet this designed by the noted architectural [mn, length of the corridor, while a number of requirement. Daniel H. Burnham and Company, are glass sidelight and transom configura­ important early high-rise office struc­ tions allowed light brought in by the Solution tures and seminal examples of the exterior windows to suffuse the hall and To retain the transoms and sidelights Chicago School of Architecture. open stairway. Mahogany trim outlined while complying with code require­ Although the buildings' office spaces all of the glazed areas, doors and wain­ ments, the architects designed a non­ were altered over the past century to suit scoting. Beginning in 1997, the combustible assembly that was integrat­ the changing desires of tenants, large Reliance Building was rehabilitated for ed into the existing wall on the hotel portions of the historic corridors sur­ use as a 122-room hotel. room side (see figure 2). The 3-'Is" thick vived to the late 1990s when the struc­ wall consisted of two gypsum boards tures were converted for new uses. The Problem separated by steel studs and sealed to the following sections discuss how the corri­ Floors eight through twelve retained existing ceiling and doorframe. Back dor features of both buildings were mod­ their original features and layouts. painting the glass white obscured the ified for increased fire protection. Because of their historical significance new wall assembly from the corridor. and because the owners intended to The mahogany office doors were RELIANCE BUILDING focus upon that significance in market­ 2-1f2" thick with upper 1/8" thick glass (Hotel Burnham) ing the hotel, rehabilitation plans were and lower if4" thick wood infill panels. Chicago, lllinois heavily influenced by a desire to pre­ Both glass and wood panels were code serve original materials and the distinc­ deficient. To increase their fire resist­ Construction of the fifteen-story tive character of the surviving space. ance, two 3/8" gypsum boards were Reliance Building was completed in Until the building underwent a major secured flush to the inside face of the 1895. With a steel structural frame, nar­ rehabilitation and its use classification glass and a single 5/ 8" sheet was used on row bands of decorative terra cotta and shifted from office to residential, original the lower wood panel (see figure 3). large bay windows, the Reliance corridor materials and features remained New wood molding stained to match the Building offered a narrow, light (and despite their non-conformance to updat­ original was placed around the border to light filled) high-rise alternative to the ed building codes. Once converted to a secure and mask the edge of the added prevailing dense masonry office building residential high-rise, however, the reha­ material. Mirrors were installed on model. The interior corridors were func­ bilitated corridors had to provide one upper panels facing the hotel rooms tional and elegant, comparable to "Class while lower panels were painted brown

~ Existing ceiling 0'- Sealan Spn'nkler head ~ • E xisting wood ~1 o 0 ~ Sealant as required as req uired m olding - abo ve each door =pi : fiii ; , New gypsum Exi sting Newgypsum board Ex isting glass board soffit glas :~I s & framing rand framing / soffit EXI sting transom ~ (en try & bath only) . (entry & bath only) oj Exi sting ~ J tran som " One hour r ated ~ Oneho I'ii!~ ,0 ur rated ~ wallassem bly 0.' wall ass embly EXI' sting T>- wo od door Inside f ace of glass painted white Ex isting glass r-- Inside face of glass Existing sid elight - painted wh ite glas s panel 23/8" gypsum board -- panels s ecured , k; : , 1~ to uppe r glass panel M arble facia ... ;, -~ r- I 5/8" gypsum board , I panel secured to I Existing wood , lower wood panel Ex isting wall : ./Sealant as required infill panel co nstruction .. New wood trim to match historic Corridor Guest Room Corridor Guest Room

Figure 2. Typical Reliance Building corridor section showing additional Figure 3. Typical Reliance Building door/transom section showing addi­ wall assembly built behind historic glass sidelight and transom. tional wall assembly and door panels. Drawing: Antunovich Associates. Drawing: Antunovich Associates. 3 have required replacing the historic escutcheon plates and knobs or significant­ ly altering the door stile. Instead, a new mortise lock set appropriate to the door rat­ ing was installed with the original knob and escutcheon plate fitted over top.

FISHER BUILDING Chicago, llIinois The main eighteen-floor section of the Fisher Building was finished in 1896 with a taller addition constructed ten years later. Like the Reliance Building, bay windows and terra cotta spandrels emphasized the height and lightness of the Fisher Building. The highly fmished interior corridors were also similar to those in the Reliance. Carrara marble wainscoting extended almost the full height of the walls, with a Figure 4. View of a Reliance Building office door Figure 5. Completed Reliance Building corridor series of three-light transoms above each from inside guest room. Upper and lower door showing historic door panel, sidelight and tran­ door. Large sidelights flanked the door­ panels have gypsum board secured to back with som. Photo: Chad Rand!. ways at some corridor ends. The new molding. A mirror was affixed to the upper mahogany doors were of two basic vari­ panel while the lower panel was painted to eties. Most had a glass upper panel and els, sidelights and transoms (see figure 5). match original material. Photo: Chad Rand!. wood infill panel below, while others had a New plain glass was used in locations single glazed panel filling almost the entire where the original was cracked or other­ (see figure 4). Like the sidelights and door area. Both types featured custom wise required replacement. Room num­ transoms, the original glass was back hardware including escutcheons with a bers were lettered on the glass with gold painted with a white latex paint to con­ Fisher Building monogram and decorative leaf. Finally, the direction of the door ceal the infill panels from the corridor. hinges. Mahogany trim delineated the swing was reversed so that they opened Intumescent paint was applied between edges of all doors, glazed areas and wain­ inward and automatic closers were added the door and frame to provide an effec­ scoting. The conversion of the Fisher in keeping with standard exiting code tive smoke barrier and compensate for Building to 184 apar1ment units began in 1998 requirements. small irregularities in the fit of the his­ as the Reliance project was conduding. Approval for these solutions had been toric doors. The mail slots were sealed obtained by submitting designs for and filled with a fire-rated putty. Further Problem upgraded doors and glazed areas to both fire protection was provided by the the Chicago Committee on Building The Fisher Building office corridors sur­ installation of a sprinkler head on the Standards and Tests and the Bureau of vived to the period of the rehabilitation corridor-side wall above each door. Fire Prevention. Following a process of with a high degree of integrity. Because its These heads were in addition to those negotiation and reviewing mock-ups function remained unchanged for over one specified by the building code. installed in the building, these agencies hundred years and because it never under­ All surviving glass (plain, fluted and determined that the proposed assemblies went a major rehabilitation project, the florentine) was retained in the door pan- matched the level of protection specified building had not been required to comply in the code. with subsequent changes to the city's Retaining the doors building code. However, when the office and corridor glazing led space was converted into apartments, all to the preservation of a the code provisions specified for residen­ host of other features, tial high-rise buildings became applicable. including the mahogany The doors, transoms and large sidelights trim found throughout were not fire resistant enough to achieve the corridors and unique the required ratings. As with the Reliance door hardware (see fig­ Building, the Fisher Building owner ure 6). Historic mag­ intended to emphasize its historical and netite hinges, mail slots, architectural significance in marketing the doorknobs and building to tenants. Preserving the public escutcheon plates corridor space, therefore, was (inscribed "Reliance") particularly important. were also retained. This meant forgoing the Solution keycards that are typical Although rehabilitation plans for the Fisher for new hotels in favor Building were similar to work completed of traditional locks and Figure 6. Original hardware including on the Reliance Building, Chicago building doorknobs, escutchen plates and hinges keys. Installing a key­ authorities reviewed each project individu­ were retained. Photos: McClier. card system would ally. Obtaining approval for the Fisher 4 behind the lower wood panel (see figure One 5/8" 8). Molding with profiles that were sim­ Existing gypsum board ilar to those on the original door was attached at the joint between the gypsum clay ---C;~~--r~".J~ panel ----. tile wall and the original doorframe. Intumescent material was also applied to the edges of the door and doorframe (see figure 9). New wood Openings into some offices were missing original doors and a few doors New wood ! Existing were missing glass. To fill in the gaps, trim to match mahogany architects attempted to match door types One 3/4" original trim and glass types (a mix of fluted, dia­ b'Ypsum Existing mond patterned, chipped patterned and board _ .. glass plain) on each floor - or floor section - using materials shifted from other areas panel panel ~ of the building or from a stockpile found Unit side Corridor side Unit side Corridor side in the basement. Where replacement glass was required, new plain glass was used. Room numbers and the names of Figure 7. Section of Fisher Building door modi­ Figure 8. Section of lower wood panel with fied to improve glass panel fire rating. Drawing: gypsum board reinforcement. Drawing: early office tenants were lettered on the Garet Stefanowski, PappageorgelHaymes. Garet Stefanowski, PappageorgefHaymes. glass to distinguish apartment units. Following the Reliance Building model, all door hardware, including Building's unrated doors and glazed the wall. Extending from the inside door hinges, knobs, escutcheons and mail areas also required comprehensive docu­ head trim to the ceiling, it consisted of slots (where present) were preserved and mentation and negotiation with the two gypsum board panels- a 3/4" panel incorporated into the rehabilitated doors Bureau of Fire Prevention and the placed directly against the glazing (after (see figure 10). New deadbolt locks and Committee on Building Standards and back painting the glass with a white peepholes were added to the door stiles Tests. paint) and a second 5/8" panel. above the original knobs. Automatic The Fisher Building corridors had Door modifications paralleled those closers were added to all doors. considerably less glazed areas than the made in the Reliance Building. The Reliance corridors. Glass was limited interior stops were removed from the primarily to transoms and door panels. glazed areas of the doors, the original Reliance and Fisher Building To increase the fire resistance of the glass was cleaned and back painted, and Project Evaluation transoms a non-combustible wall assem­ a 3/4" sheet of gypsum board was By introducing new fire resistant assem­ bly, similar to that used in the Reliance, secured against the glass (see figure 7). blies and mechanical upgrades in the was constructed on the apartment-side of A 5/ 8" sheet of gypsum board was used already altered office spaces, there was no impact upon the scale of the corridors and the views along their length (see fig­ ure 11). Although the construction of new interior walls preserved the tran­ soms and sidelights and the continued appearance of the corridor, it did obscure the glazed areas and their moldings from inside the former tenant space. Painting the inside face of the glass panels also resulted in a visual change in the corri­ dor. Back painting was necessary in order to hide the gypsum infill panels, but the result lacked depth and failed to suggest the original office space within. The change was less noticeable in areas with patterned glass where the texture provided some relief from the flat, span­ drel-like appearance of the new assem­ bly. Covering the glazed panels with solid materials also darkened what were once daylight-flooded corridor spaces. With the continuing evolution of fITe resistant materials and increased accept­ ance of building codes specific to his­ toric properties, it is hoped that future Figure 9. Fisher Building door viewed from Figure 10. Completed Fisher building corridor projects will be able to improve upon the apartment showing gypsum board infill with back painted door and tripartite transom. techniques described in this Tech Note. panels, new trim and retained hardware. Photo: National Park Service File. Developments in fire-rated glass tech­ Photo: National Park Service File. nology offer the possibility of using 5 to retain historic features. In concert Project Data: with local code officials, architects and flre protection engineers can develop Reliance Building equivalent safety measures to retain and (Hotel Burnham) upgrade the flre resistance of surviving Chicago, IL door assemblies and glazed areas. Preserving these major assemblies makes Project Dates: 1997-1999 possible the retention of other features such as original moldings and door hard­ Architect: ware, as well as the dimensions and floor Antunovich Associates plan of the historic corridors. The Fisher Chicago,IL and Reliance building rehabilitation proj­ ects are good examples of how historic Consultant: corridors can be sensitively modifled to McClier ensure occupant safety and the continued Chicago, IL existence of the historic resource. Fisher Building Additional Reading Chicago,IL • Guideline on Fire Rating ofArchaic Project Dates: Materials and Assemblies. Washington, 1999-2001 DC: U.S. Department of Housing and Urban Development, Office of Policy Architect: Development, February 2000. Pappageorge/Haymes Ltd. Figure 11. View of the completed Reliance • Kaplan, Marilyn E. "Safety, Building Chicago, IL Building corridor. Photo: McClier. Codes and Historic Buildings," Historic Preservation Information Booklet, Consultant: glass sheets rather than solid gypsum Washington, DC: National Trust for Baldwin Historic Properties board behind the historic transoms and Historic Preservation. Chicago, IL door panels. New rehabilitation code • NFPA 914 Code for Fire Protection of provisions may permit transoms to be Historic Structures. Quincy, MA: retained without the addition of flre National Fire Protection Association, resistant panels if they are sealed in a 2001. flxed position and have double coverage • Pianca, Elizabeth G. "Smart Codes: A sprinklers installed above the openings. New Approach to Building Codes," Both solutions will thus allow the light Forum News May/June 2001. qualities of historic transoms, doors and • Solomon, Robert E., PE. "Preserving sidelights to be more easily and effec­ History from Fire. Bridging the Gap tively preserved. Between Safety Codes and Historic Buildings," Old House Journal, Conclusion Nov.lDec. 2000, 41. • Timber Panelled Doors and Fire. Life safety regulation and historic Upgrading the Fire Resistance preservation need not be mutually exclu­ Performance of Timber Panelled Doors sive. In the case studies presented and Frames. London, England: English above, similar treatments were used to Heritage, 1997. reconcile code provisions and the desire

THIS PRESERVATION TECH NOTE was prepared by the techniques for successfully maintaining and preserving cultural National Park Service. Charles E. Fisher, Heritage Preservation resources. All techniques and practices described herein con­ Services, National Park Service, serves as the Technical Editor form to established National Park Service policies, procedures of the PRESERVATION TECH NOTES. Information on the and standards. This Tech Note was prepared pursuant to the Fisher and Reliance building projects was generously provided National Historic Preservation Act, which direct the Secretary of by Garet Stefanowski of Pappa george/Haymes Ltd., and Jeff the Interior to develop and make available to government agen­ Zelisko of Antunovich Associates. Special thanks are extended cies and individuals information concerning profesional methods to Marilyn E. Kaplan of Preservation Architecture, Jack Watts of and techniques for the preservation of historic properties. Fire Safety Institute, Brian C. Olson, PE, of the National Park Service's Denver Service Center and Kaaren Staveteig, Antonio Comments on the usefulness of this information are welcomed Aguilar, Sharon C. Park and Kay D. Weeks of the National Park and should be addressed to PRESERVATION TECH NOTES, Service's Heritage Preservation Services for their review and Technical Preservation Services - NC200, National Center for comments. Thanks also to Douglas Gilbert and Gunny Harboe Cultural Resources, National Park Service, 1849 C Street, NW, ofMcClier, for providing photographs. Washington, DC 20240.

PRESERVATION TECH NOTES are designed to provide practical information on traditional practices and innovative ISSN: 0741-9023 PTN43 September 2001 6